Apparatus for spinning multicomponent fibers



1968 KAZUMI NAKAGAWA ETAL 3,403,422

APPARATUS FOR SPINNING MULTI-COMPONENT FIBERS Filed June 28, 1965 I nvenlor 5' By wwl/ va/A tlorney;

United States Patent M 3,403,422 APPARATUS FOR SPINNING MULTI- COMPONENT FIBERS Kazumi Nakagawa, Saidaiji, Nobuhiro Tsutsui, Okayama, and Keiichi Zoda, Saidaiji, Japan, assiguors to Japan Exlan Company Limited, Osaka, Japan Filed June 28, 1965, Ser. No. 467,509 Claims priority, application Japan, July 2, 1964,

39/ 37,732 1 Claim. (Cl. 188) ABSTRACT OF THE DISCLOSURE Apparatus for spinning multi-component fibers which have a zigzag or wavy interfacial junction between the materials, said junction extending transversely of the direction of flow. The two materials are flowed in laminar flow through separate material supply means, and then through respectively alternate grooved passages into a common narrow slit extending along a row of orifices in a spinnerette plate. As the material flows into the slit through the grooved passages from opposite side in laminar flow, it forms the wavy interfacial junction, and this junction is maintained as the material is extruded through the spinnerette plate.

This invention relates to improvements in the production of multi-component, composite or conjugated fibers. More particularly, this invention relates to apparatus for producing multi-component fibers wherein two or more different components are laminated or conjugated longitudinally of the fibers with a zigzag or wavy interfacial juncture across the fiber to provide a larger area of interfacial junction between the different components forming, the fibers so as to prevent delamination of these different components.

It is well known to produce multi-component fibers from at least two different fiber-forming spinning materials by extruding them concurrently through a common orifice. Due to the difference in thermal shrinkage or swelling between these different materials of which such composite fibers are composed, coily crimps may be developed therein.

The known multi-component fibers, however, have drawbacks that the components of the fibers tend to be peeled off or delaminated. This tendency is more pronounced when the physical and chemical properties of the components are more different in order to improve the crimping characteristics. When the fiber components are so peeled off or delaminated the crimping characteristics are lost and the appearance of the final products made of such fibers is adversely affected.

Therefore, it is an object of this invention to provide composite fibers wherein two or more components are conjugated together firmly without a danger of delamination thereof.

It has been found that this object is accomplished, accoding to this invention, by providing a zigzag or Wavy interfacial junction across the fiber to increase the area of the interfacial junction between the different components.

It has also been found that such a zigzag or wavy interfacial junction can be formed by causing the flows of the different fiber-forming materials through the respective passages which mesh with each other to form a zigzag or wavy interfacial line in cross section, before they flow in laminar flow toward an orifice for being extruded therethrough. When these materials are merged into a common channel through the respective passages they flow through said channel in laminar flow with the interfacial zigzag juncture between the different materials.

3,403,422 Patented Oct. 1, 1968 According to this invention there is also provided an apparatus to create the desired zigzag interfacial juncture. Thus, according to this invention, there is provided a spinning apparatus which includes means for separately supplying a plurality of different fiber-forming materials, a narrow channel for receiving each of said materials, said narrow channels merging into a common narrow slit communicating with orifices, characterised by first passages for one material between one narrow channel and the narrow slit and second passages for the other material between next narrow channel and the narrow slit, these first and second passages being so formed and arranged alternately that the different fiber-forming materials from respective channels flow through the respective passages into the common slit in laminar flow with a zigzag interface in cross section.

The invention will be described in more detail by referring to the accompanying drawings wherein:

FIG. 1 is a longitudinal section of a device embodying the invention;

FIG. 2 is an enlarged view of a part of FIG. 1;

FIG. 3 is a perspective view of FIG. 2;

FIG. 4 is a cross section taken on the line A-A' of FIG. 2;

FIG. 5 is a cross section taken on the line BB of FIG. 2;

FIG. 6 is an enlarged cross-sectional view, schematically represented, of the fiber obtained by the invention.

Referring to FIGS. 1, 2 and 3, there is illustrated a spinning device for producing bi-component fiber embodying this invention, which comprises a spinnerette plate 2 having orifices 1 arranged in rows spaced from each other. The plate 2 is mounted on a guide plate 4 having slits 3, there being the same number of slits as there are rows of orifices 1. These plates 2 and 4 are mounted and assembled on a sleeve 5 and at the end of supply tube 8 by means of a cap 6 and nut 7. The inlet section of the cylindrical sleeve 5 which is inserted and held in the supply tube 8 is provided with a bafile (not shown) which serves to divide the inlet section into two chambers 9 and 10. One spinning solution is supplied to one chamber 9 and the other is supplied to the other chamber 10. The outlet section of the cylindrical sleeve 5 is provided with a plurality of narrow channels 12, 12' defined by partition walls 11. The arrangement is such that the channels 12 and 12' are connected with the respective chambers 9 and 10 so that alternate channels are supplied one solution and the remaining channels are supplied with the other solution. In operation, the first spinning solution flows from one chamber 9 to alternate channels 12 and down into the associated slit 3 toward orifices 1. The second spinning solution flows from the other chamber 10 to alternate channels 12 and also down into the associated slit 3. In the common slit 3, the two different solutions flow in laminar flow down to the row of orifices 1 into a coagulation bath (not shown) to form composite fibers. The construction and function of a spinning device of this type is more fully described in US. Patent No. 3,182,106 of May 4, 1965 and reference should be made to this patent for further details.

The important feature of this invention is in the provision of special passages between the channel 12, 12' and the slit 3 so that when one solution from the channel 12 and the other solution from the adjacent channel 12' flow together into the common slit in laminar flow there is formed a zigzag or wavy interfacial junction between the solutions in cross section of the laminar flow. In the embodiment shown, a plurality of grooves 15 is formed across the lower edge portion on one side of the partition wall 11 for communication with the channel 12 and the slit 3, while corresponding grooves 15' are formed across the lower edge portion on the other side of the partition wall 11 side for communication with the other channel 12' and the same slit 3. These grooves 15 and 15' are alternately arranged as shown so that the solutions discharged from these grooves will alternately mesh with one another and flow into the common slit 3 in laminar flow with a zigzag or wavy interfacial junction in cross section as well shown in FIG. 5. The pitch of the grooves 15 and 15' and consequently the pitch of the resulting interfacial undulations in the laminar flow within the slit 3 must be smaller than the root or base diameter of the orifice 1.

Since the said laminar fiow with said zigzag interfacial junction is extruded with this condition through orifices 1 into a coagulating bath (not shown), there are formed composite fibers having the corresponding zigzag or wavy interfacial junction in cross section as shown in FIG. 6. Due to the zigzag, wavy or undulated interfacial junction the area through which the two components are conjugated or laminated is increased as compared with the case where these two components are conjugated through a shorter straight interfacial junction, and con sequently the two components in the fiber of this invention are more firmly joined and are not easily delaminated or peeled off.

This invention can be applied not only to a wet spinning process but also to a melt spinning process. This application is applicable to spinning of any fiber-forming material such as acrylonitrile polymers, polyamides, polyesters, polyvinyl chlorides, polyvinyl alcohols, polyolefins, cellulose acetates, viscose, etc. so far as the production of multi-component fibers is concerned.

This invention will be further described in detail by way of the following example, it being to be understood, however, that the scope of this invention is by no means limited thereto. All parts are by weight.

Example Two spinning solutions were prepared respectively from a copolymer A (intrinsic viscosity 1.5 dl/g. in DMF) consisting of 90 parts acrylonitrile and 10 parts methyl acrylate and a copolymer B (intrinsic viscosity 1.5 dl./ g. in DMF) consisting of 87 parts acrylonitrile and 13 parts methyl acrylate, by dissolving each polymer in a 45 aqueous solution of sodium thiocyanate to be a 10% solution.

These two spinning solutions were extruded through the spinning device of FIGS. 1-5 into a coagulating bath comprising a 10% (by weight) aqueous solution (-3 C.) of sodium thiocyanate to form composite fibers.

In order to observe how the two components had been conjugated, the dry fibers prepared above were dyed and heat treated so as to allow the dye to diffuse sufiiciently into the fiber structure. Then the cross-section of the -fiber was observed under a microscope. There was observed an undulated inter-facial junction as shown in The fibers were spun into yarns, which were then knit into a fabric. No delamination' of the fiber components was observed during the mechanical processing. When heat treated in a usual manner the yarns developed very satisfactory coily crimps.

What we claim is: I p v 1. An apparatus for spinning multicomponent fibers from at least two difierent fiber-forming materials, which comprises first supply means for supplying the first of the ditferent fiber-forming materials and a second separate supply means for supplying the second of said difierent fiber forming materials, a narrow channel extending from each of said means for supplying the materials, slit defining means defining at least one common narrow slit, a spinnerette plate having a row of orifices therein into which said common narrow slit opens, said apparatus having a plurality of first grooved passages extending between one narrow channel and the narrow slit and spaced from each other along the length of said slit, and said apparatus further having a plurality of second grooved passages extending between the other narrow channel and the narrow slit, said second grooved passages alternating with said first grooved passages, said grooved passages receiving said different fiber-forming materials and causing them to flow in laminar fiow into said narrow slit, the pitch of said grooves in the direction of the length of said slit being less than the root diameter of the orifices in said spinnerette plate.

References Cited UNITED STATES PATENTS 2,815,532 12/1957 'Brannlich 264171 2,936,482 5/1960 Kilian 264-171 3,182,106 5/1965 Fujita et al. 264168 X 3,188,689 6/1965 Breen 264171 X 3,295,552 1/1967 Powell et a1 264171 X 3,308,503 3/1967 Fays et al. 188 3,318,987 5/1967 Fitzgerald 264-168 X 3,341,891 9/1967 Shirnizn et al.

FOREIGN PATENTS 621,433 12/1962 Belgium.

823.603 11/ 1959 Great Britain. 3,816,330 8/1963 Japan. 3,824,246 11/1963 Japan.

JULIUS FROME, Primary Examiner.

I. H. WOO, Assistant Examiner. 

